The text messages between Peter Strzok and Lisa Page have drawn the attention of lawmakers and the Department of Justice Inspector General’s Office because they appear to illustrate animus against President Donald Trump from two people involved in special counsel Robert Mueller’s investigation of Russian interference in the 2016 election.

Strzok--whose work on the 2016 investigation of Democratic nominee Hillary Clinton’s email practices as secretary of state has also come under scrutiny--was removed from Mueller’s team when thousands of texts between the two, who were reportedly having an affair, were found last summer. Page had already completed her work with Mueller’s team at that time.

Members of Congress were previously provided with hundreds of pages of their texts, but they learned last week that texts from Dec. 14, 2016 to May 17, 2017 were missing. In a letter to Sens. Chuck Grassley, R-Iowa, and Ron Johnson, R-Wis., Inspector General Michael Horowitz said Thursday that forensic tools have been able to recover some of those texts and efforts find others are still underway.

Republicans raised questions earlier this week about how text messages from the five-month period stretching from Trump’s transition to around the time Mueller was appointed were lost, but FBI officials said a technical glitch prevented the archiving of texts from many devices during that time.

"When they have missing emails and things like that that are very relevant to what went on or didn’t go on, something’s wrong, I believe," Sen. Richard Shelby, R-Ala., told WPMI Wednesday. "I would be very suspicious.”

In the text messages that have been made public so far, Strzok and Page were highly critical of then-candidate Trump and many other people. One message vaguely referred to having an “insurance policy” in the event Trump was elected.

Sen. Johnson released additional messages Wednesday, including some in which Strzok appears reticent to join Mueller’s team and doubtful that it will uncover anything. Johnson and others have also suggested a post-election text referring to forming a “secret society” was evidence of a plot against Trump, but Johnson acknowledged Thursday it may have just been a joke.

"It's a real possibility," he told Sinclair Broadcast Group on Thursday morning.